Methods and apparatus for mixing foundry sand



J. 5. DEACON 3,070,858

METHODS AND APPARATUS FOR MIXING FOUND-RY SAND Jan. 1, 1963 Fild June 22, 1959 FIG! FIG.2

- INVENTOR.

JAMES s. DEACON/' ATTOR NEY United States Patent 3,070,858 METHODS AND APPARATUS FOR MIXIN FOUNDRY SAND James S. Deacon, 946 Oak St., Beloit, Wis.

Filed June 22, 1959, Ser. No. 821,763

4 Claims. (Cl. 2289) in order that the molding sand is properly conditioned 1 it should be discharged from the mixer at proper temperature and proper moisture and additive content in order to insure proper functioning and efficiency.

It is a principal object of this invention effectively and eificiently to provide apparatus and a method for metering bentonite, fireclay or other additives into an air stream of suflicient carrying velocity, and to transport or convey these materials from their storage hoppers to a mixing chamber, and then at a controlled rate with water form a slurry which is discharged at a proper time for mixing with the sand. Another object is to provide an improved apparatus' and method'ifor introducing additives to the sand batch,

blending the proper additives with proper amounts of water, all prior to introducing them to a measured sand batch, and to provide a method and apparatus for measuring and conveying these additives from storage to the sand mixer.

Another object is to provide a method and apparatus of the character described which will regulate the amount of water and compensate automatically for temperature and moisture variations in the sand.

Other and further objects of the invention will become apparent as the description proceeds, when taken in conjunction with the drawings, in which:

FIG. 1 is a flow diagram illustrating the method and apparatus according to the present invention; and

FIG. 2 shows apparatus for obtaining the proper amount of water for the sand batch, and also apparatus for measuring the pH of a water suspension of the additives to adjust the flow rate of the additives from the storage hoppers to the water.

Referring now to the drawing, FIG. 1 shows a pair of hoppers 10 and 11 which respectively store certain additives such as fireclay and bentonite. Hoppers 10 and 11 are each equipped with conventional means shown as 12 for metering the flow therefrom, and the hoppers 10 and 11 feed their respective products into an air stream maintained in a transfer duct 13 which acts as a conveyor for these additives to a separator or blender 14. Blender 14 is of the wet scrubber type and is equipped with a motor driven exhaust fan 15 with an outlet 16' for the exhaust air, the fan 15 moving the air and the additives carried thereby in the transfer duct 13.

As the additive laden air enters the separator 14, the additives therein fall by gravity to the bottom thereof, being separated from the air transport vehicle by the scrubber eflect of the separator 14. The separator 14 has a hopper 17 at the bottom thereof which is arranged to discharge into a slurry tank 18.

Water is supplied to the slurry tank 18 by a pipe 19, and the flow of water to the slurry tank 18 is controlled by a valve 20. However, the slurry is recirculated through the bender 14 by means of a pump 21 having 70 its intake connected to the slurry tank 18 and its discharge line 22 connected to the blender 14.

"ice

As seen in FIG. 1, the slurry tank 18 is arranged to discharge into a sand mixer 23, see FIG. 2, by means of a duct 24, the discharge being controlled by a dump valve 25.

Referring now particularly to FIG. 2, the temperature and moisture content of the batch within the sand mixer 23 is arranged to be measured to control the amount of water in the tank 18, and the pH of the slurry mixture is also measured to determine whether the water is of a prescribed pH for addition to the sand batch within the mixer 23.

The temperature and moisture content of the water in the mixer 23 is accordingly measured by a moisture and temperature measuring device 26 which reflects a reading into the valve 20 to determine the total amount of water needed for the sand batch in mixer 23.

The amount of such water is measured by a float operated valve 27 which reflects a measurement of the quantity of water in the slurry tank 18 into the water control valve 20. When the level within the slurry tank 18 corresponds to the total amount required as determined by the moisture and temperature reading device 26, the supply of water to the slurry tank 18'is shut off.

The pH of the water within the slurry tank 18 is also a measure of the quantity of additives to the Water, and the pH is accordingly measured by a pH measuring device 28. The measurements obtained thereby are employed to meter the supply of additive from hoppers 10 0 component parts for carrying on the method and apparatus of the invention, changes in the form and configuration may be made without effecting their operativeness, and the right to make such changes without departing from the spirit of the invention and the scope of the claims is reserved.

Having thus described my invention, what I claim and desire to secure by Letters Patent in the United States is:

1. In apparatus for conditioning foundry sand, a slurry tank for additives and water, means for adding water to said slurry tank including valve means for controlling said water, a separator adapted to discharge additive and water into said slurry tank, means for circulating additive and water from said slurry tank to said separator, at least one hopper containing additive, a duct connected between said separator and said hopper including means for moving additive-laden air to said separator, means interposed between said duct and said hopper for metering the amount of additive moved in said duct, a mixer for a batch of foundry sand, said mixer being adapted to receive the additive-water mixture from said slurry tank. means for measuring the temperature and moisture content of said batch, means for measuring the amount of slurry in said slurry tank, both of said measuring means actuating means controlling said valve means, and means for measuring the pH of said slurry, said last named means controlling said metering means.

2. In apparatus for conditioning foundry sand, a slurry tank for additives and water, means for adding water to said slurry tank including means for controlling said water, a separator adapted to discharge additive and water into said slurry tank, means for circulating additive and water from said slurry tank to said separator, at least one hopper containing additive, a duct connected between said separator and said hopper including means for moving additive-laden air to said separator, means interposed between said duct and said hopper for metering the amount of additive moved in said duct, a mixer for a batch of foundry sand, said mixer being adapted to receive the additive-water mixture from said slurry tank, means for measuring the temperature and moisture content of said batch, means for measuring the amount of slurry in said slurry tank, both of said measuring means actuating means controlling said first named means, and means for measuring the pH of said slurry, said last named means controlling said metering means.

3. In apparatus for conditioning foundry sand, a slurry tank for additives and water, means for adding water to said slurry tank including valve means for controlling said water, a separator adapted to discharge additive and water into said slurry tank, means for circulating additive and water from said slurry tank to said separator, at least one hopper containing additive, a duct connected between said separator and said hopper including means for moving additive from said hopper to said separator, means interposed between said duct and said hopper for metering the amount of additive moved in said duct, a mixer for a batch of foundry sand, said mixer being adapted to receive the additive-water mixture from said slurry tank, means for measuring the temperature and moisture content of said batch, means for measuring the amount of slurry in said slurry tank, both of said measuring means actuating means controlling said valve means,

and means for measuring the pH of said slurry, said last named means controlling said metering means.

4. In apparatus for conditioning foundry sand, a slurry tank for additives and water, means for adding water to said slurry tank including means for controlling said water, a separator adapted to discharge additive and Water into said slurry tank, means for circulating additive and water from said slurry tank to said separator, at least one hopper containing additive, a duct connected between said separator and said hopper including means for moving additive from said hopper to said separator, means interposed between said duct and said hopper for metering the amount of additive moved in said duct, a mixer for a batch of foundry sand, said mixer being adapted to receive the additive-water mixture from said slurry tank, means for measuring the temperature and moisture content of said batch, means for measuring the amount of slurry in said slurry tank, both of said measuring means actuating means controlling said first named means, and means for measuring the pH of said slurry, said last named means controlling said metering means.

References Cited in the file of this patent UNITED STATES PATENTS 

1. IN APPARATUS FOR CONDITIONING FOUNDRY SAND, A SLURRY TANK FOR ADDITIVES AND WATER, MEANS FOR ADDING WATER TO SAID SLURRY TANK INCLUDING VALVE MEANS FOR CONTROLLING SAID WATER, A SEPARATOR ADAPTED TO DISCHARGE ADDITIVE AND WATER INTO SAID SLURRY TANK, MEANS FOR CIRCULATING ADDITIVE AND WATER FROM SAID SLURRY TANK TO SAID SEPARATOR, AT LEAST ONE HOPPER CONTAINING ADDITIVE, A DUCT CONNECTED BETWEEN SAID SEPARATOR AND SAID HOPPER INCLUDING MEANS FOR MOVING ADDITIVE-LADEN AIR TO SAID SEPARATOR, MEANS INTERPOSED BETWEEN SAID DUCT AND SAID HOPPER FOR METERING THE AMOUNT OF ADDITIVE MOVED IN SAID DUCT, A MIXER FOR A BATCH OF FOUNDRY SAND, SAID MIXER BEING ADAPTED TO RECEIVE THE ADDITIVE-WATER MIXTURE FROM SAID SLURRY TANK, MEANS FOR MEASURING THE TEMPERATURE AND MOISTURE CONTENT OF SAID BATCH, MEANS FOR MEASURING THE AMOUNT OF SLURRY IN SAID SLURRY TANK, BOTH OF SAID MEASURING MEANS ACTUATING MEANS CONTROLLING SAID VALVE MEANS, AND MEANS FOR MEASURING THE PH OF SAID SLURRY, SAID LAST NAMED MEANS CONTROLLING SAID METERING MEANS. 